[PATCH 04/13] drm/i915/dmc_wl: Get wakelock when disabling dynamic DC states

[Luca Coelho]

On Mon, 2024-10-21 at 19:27 -0300, Gustavo Sousa wrote:
> Bspec says that disabling dynamic DC states require taking the DMC
> wakelock to cause an DC exit before writing to DC_STATE_EN. Implement
> that.
> 
> In fact, testing on PTL revealed we end up failing to exit DC5/6 without
> this step.
> 
> Bspec: 71583
> Signed-off-by: Gustavo Sousa <gustavo.sousa at intel.com>
> ---
>  .../drm/i915/display/intel_display_power_well.c    | 10 +++++++---
>  drivers/gpu/drm/i915/display/intel_dmc_wl.c        | 14 ++++++++++++--
>  drivers/gpu/drm/i915/display/intel_dmc_wl.h        |  2 ++
>  3 files changed, 21 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_power_well.c b/drivers/gpu/drm/i915/display/intel_display_power_well.c
> index adaf7cf3a33b..e8946ce86aaa 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_power_well.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_power_well.c
> @@ -987,10 +987,14 @@ void gen9_disable_dc_states(struct intel_display *display)
>  		return;
>  	}
>  
> -	gen9_set_dc_state(display, DC_STATE_DISABLE);
> -
> -	if (!HAS_DISPLAY(display))
> +	if (HAS_DISPLAY(display)) {
> +		intel_dmc_wl_get_noreg(display);
> +		gen9_set_dc_state(display, DC_STATE_DISABLE);
> +		intel_dmc_wl_put_noreg(display);
> +	} else {
> +		gen9_set_dc_state(display, DC_STATE_DISABLE);
>  		return;
> +	}

I think intel_dmc_get/put() already protect indirectly on
HAS_DISPLAY(), doesn't it? If that's the case, then the if here is
unnecessary.

--
Cheers,
Luca.